Health disparities continue to exist between and within populations and little is known about the causes of population differences observed in tobacco use, nicotine dependence, and related diseases. More importantly, an age-race paradox exists in which African American youth consistently report lower prevalence of tobacco use than their Caucasian counterparts, yet African American adult smokers suffer a disproportionate burden of tobacco-related morbidity and mortality. Nicotine dependence is the most formidable impediment to quitting smoking among adolescents. Despite the recognition of the central role of nicotine dependence in smoking cessation, there is a paucity of information about how nicotine dependence is expressed among youth who smoke. For these reasons, researchers have called for additional research to address the insufficient understanding of and gap in the literature on adolescent nicotine dependence and its impact on cessation. Thus, I describe a plan to examine critical factors of nicotine dependence among urban African American youth utilizing individual and group (class) trajectory analysis (Study 1) as well as mixed methods research, including a validated measure of nicotine dependence, focus groups, and in-depth interviews (Study 2) to elucidate the complexities of adolescent nicotine dependence. PUBLIC HEALTH RELEVANCE: African Americans bear the greatest burden of death and illness due to cigarette smoking. Most adults began smoking as adolescents and nicotine dependence is a critical barrier in quitting smoking. This Award will allow me to examine the nicotine dependence experiences of both adults and youth to better understand how we can help African American youth quit smoking.